New chick

One of my bantams became broody and we let her sit on the eggs in her own run, protected from the weather.  Only one hatched (now 4 days old) and seems to be doing well, the other 3 eggs she left, two of which looked almost complete, she had kicked out 2/3 others early on.

Now this is my first time as Mum and given my rubbish success rate - 1 out of 7 eggs, so am keen not to let the little one down.

Mum and babe are in the run, fresh water and chick crumbs every day.  Only one side of the run is exposed, so plenty of fresh air but protected from wind / rain (luckily non at the moment).

Anything else I should do?
How long on chick crumbs?
Anything else we should feed?  Should Mum have grit?
What age to move to growers?

Oh so many questions I feel totally hopeless.  All help gratefully received.
Thanks!

We have one of our broodies with chicks in a rabbit hutch with a movable run.  It is easier to move on the lawn every few days.  They are let out to freerange under supervision.  I have started to mix the chick crumb with growers pellets this week (6) so they get used to the new food.  I did give them some budgie grit which is suitable for chicks but they will get more grit from the garden if they need it.

Good luck with your chick and don't forget to post some pictures.   

Cider Apple Vinegar in the water is a good idea, on occasion I will get the odd chick that seems to stop thirving CAV has always pulled them round so now I use it all the time.
I mix 5ml to eacdh 1ltr of water 

Thanks again, cider vinegar is very useful - I use in my ponies feed sometimes same reasons and on the feet as good general cleaner if any minor probs.